Parliament’s portfolio committee on mineral resources has condemned Sibanye Gold after more than 900 of its workers were trapped underground as a result of a power outage.

The mining company said on Thursday that the blackout at its Free State mine was caused by a storm. However‚ the committee said that Sibanye should have had a backup plan.

“It is utterly unacceptable that an underground mine whose operation takes place under the light of a bulb could attribute its failure to bringing workers on the surface to a power outage. This goes to demonstrate the attitude of management towards safety‚” committee chairperson Sahlulele Luzipo said in a statement.

Sibanye spokesperson James Wellsted said on Thursday that a severe storm on Wednesday had damaged two Eskom power lines‚ leaving night shift workers trapped beneath the surface. Wellsted said the workers were not at risk and had been given food and water via a capsule.

The committee called for a “better and decent explanation” and urged the Department of Mineral Resources “to act swiftly and take drastic actions to such acts of carelessness.” It expressed its hope that the workers be brought to the surface well and alive.